1. Field of the Invention
The present invention relates to a bearing system for a wheel of a motor vehicle or the like.
2. Description of the Related Art
FIG. 3 shows a conventional bearing system for a wheel of a motor vehicle. The conventional bearing system includes a hub 4 having a flange 3 secured either to the wheel or to a support member on the vehicle body. The hub extends outward in the radial direction of the wheel at one end of a cylindrical portion 2, having a bearing seat 1 proximate the outside circumferential surface of the portion. A separable double row anti-friction bearing 9 includes rolling elements 5 rotatably disposed between an outer race 7, and a pair of inner races 8 fitted on the bearing seat of the hub. Outer race 7 is provided for two raceway trucks for the rolling elements, and is further integrally formed with a flange 6, located on the outside circumferential surface of the outer race and secured either to the wheel or to the support member and not to the flange 3. The outside diameter of the shoulder 10 of the hub 4 is configured smaller than that of each of the inner races 8. This configuration enables a pull-off tool to engage with the side surface of the inner race on the shoulder, in order to pull off the inner race from the hub and disassemble the hub and the bearing 9 from each other. A bearing system of this kind was disclosed in the Japanese Utility Model Application (OPI) No. 117626/80 (the term "OPI" as used herein means an "unexamined published application").
The strength of the hub 4 of the conventional bearing system needs to be maintained or enhanced. However, if the rim between the side surface 10' of the shoulder 10 and the bearing seat 1 of the cylindrical portion 2, and the inner circumferential edge of the inner race 8 located on the shoulder are enlarged in order to maintain or enhance the strength of the hub 4, the surface pressure between the side surface 8' of the inner race and that of the shoulder 10' is increased, thereby adversely affecting the strength of the hub. Further, if the outside diameter of the shoulder 10 is made nearly equal to or larger than that of the inner race 8 in order to decrease the surface pressure between the side surface 8' of the inner race and that of the shoulder 10', it is difficult to disengage the inner race from the hub 4 after the bearing system is assembled. A solution to this problem is required.
The present invention was made in order to solve this problem.
It is therefore an object of the present invention to provide an enhanced strength bearing system for the wheel of a vehicle.
It is a further object of the present invention to provide an enhanced strength bearing system which can be easily disassembled.
Additional objects and advantages will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.